AB1344 THE ROLE OF ULTRASOUND CRITERIA IN PREDICTING THE OUTCOME OF EARLY UNDIFFERENTIATED ARTHRITIS OF THE SMALL JOINTS OF THE HAND
Authors: N. Aleksandrova, A. Aleksandrov, N. Nikitina, V. Aleksandrov
Journal: Annals of the Rheumatic Diseases (2022)

Background Arthritis of peripheral joints is among the most frequent manifestations in the onset of rheumatic diseases. Determining its nosological identity and rational therapy at an early stage is a complex clinical problem. Objectives To evaluate the possibility of using hand ultrasound to predict the outcome of early undifferentiated arthritis (EUA). Methods Since 2018, patients with a first-time diagnosis of early undifferentiated arthritis were consecutively included into the study. The final group consisted of 102 patients (women, 71.6%; mean age 44.8±17.2 years old) who were prospectively observed at baseline, after 3 months, and after 1 year. Ultrasound examination (ultrasound) of the hand joints was performed according to a standard technique using a 5-12 MHz linear transducer on an Accuvix V10 ultrasound diagnostic system (Samsung Medison, South Korea). Ultrasound was performed twice with the following criteria: 1) synovium thickness, 2) blood flow in synovium by Doppler, 3) presence of hyperechogenic inclusions in synovium, 4) cortical bone contour, 5) signs of tendon inflammation (flexors and extensors of the fingers). Synovium thickness in the hand joints over 3 mm was interpreted as synovial thickening [1]; appearance of blood flow from the contour of the cortical bone of the joint with tree branching — as “pannus”, single loci of blood flow by Doppler — as synovitis in hyperemia stage. Results During 12 months of follow-up, 47 patients (46.1%) were diagnosed with early rheumatoid arthritis (based on clinical diagnosis according to 2010 criteria and/or prescription of basal anti-inflammatory drugs); 16 (15.7%) had reactive arthritis associated with urogenital infection; 7 (6.9%) had gouty arthritis; 3 (2.9%) had psoriatic arthritis; 2 (1.9%) had systemic lupus erythematosus; 1 patient (0.9%) was found to have a renal malignancy; 26 (25.5%) had no change in EUA diagnosis. Retrospective analysis of the data showed that initially patients with rheumatoid arthritis (RA) in 46.8% (22/47) were determined to have a tree-like blood flow in the synovium of the joint from the cortical contour of the bone (“pannus”); in patients with reactive arthritis associated with urogenital infection, axial tendon lesions were found most frequently (43.8%; 7/16); in patients with gouty arthritis, changes in the triangular cartilage and hyperechogenic inclusions in the synovium were more common (42.9%; 3/7). During the initial examination of patients with EUA who were subsequently diagnosed with RA, the ultrasound picture of the hand joints in the overwhelming percentage of cases (83%; 39/47) was characterized by the presence of extensor tenosynovitis and/or synovial thickening with Doppler blood flow (against the background of symmetrical arthritis of the metacarpophalangeal joints). The sensitivity of detection of these criteria to the development of RA in patients with small joint EUA was 56% with a positive prognostic value of 69%. It has been previously demonstrated that in EUA the presence of subclinical inflammation of the major joints and high titers of antibodies to cyclic citrullinated peptide are strong predictors of RA development [2]. Probably, the combination of clinical and serological tests with the presented ultrasound data of small joints can also increase the accuracy of diagnosis of early RA in patients with EUA. Conclusion Detection of subclinical inflammation in the small joints of the hand and synovial thickening with Doppler blood flow in patients with EUA at baseline can help in the stratification of patients at high risk of developing RA. References [1]Aleksandrova N.V., Aleksandrov A.V. The role of ultrasound criteria in assessing pain syndrome in the knee joint in patients with rheumatoid arthritis and osteoarthritis. Annals of the Rheumatic Diseases. 2021;80(S1):1423. DOI: 10.1136/annrheumdis-2021-eular.3224. [2]Zabotti A., Finzel S., Baraliakos X., Aouad K., Ziade N., Iagnocco A. Imaging in the preclinical phases of rheumatoid arthritis. Clin Exp Rheumatol. 2020;38(3):536-542. Disclosure of Interests None declared